Good evening,
In the 2nd photo, yes he is still in the machine gun corps. But not for much longer as they were disbanded in 1922. He is wearing khaki drill with shorts, boots and short puttees with hose tops. Army socks were only ankle length, still are, so with the short puttees you wore hose tops which were socks with no foot. The junction of sock and hose top was hidden by the puttees. He is wearing what looks to be ribbons for the war medal and victory medal.
Now, the 1st photo! I don't know quite what to make of this. As far as I can see this is not military in any way. The gent seated with breast pockets has the closest to a military uniform but the collar is wrong. The others appear to be home made? The odd ribbons on the breast are not medal ribbons. 3 of them seem to be wearing white scarves, again not military in any way. The gent on the left has what looks to be a MGC flash but this is wrong for military uniform at this time. It should be brass letters on epaulettes on the top of the shoulder.
We will have to see what anyone else thinks.
John915